1. Field of the Invention
The invention generally relates to an electrode, such as a showerhead assembly, having a tightly fitted ceramic insulator.
2. Description of the Prior Art
In large area, rectangular PECVD chambers used for processing substrates larger than 1.5 meter square, the tendency to experience arcing around the perimeter of the driven electrode is greater than smaller chambers operating under the same intrinsic processing conditions, such as RF frequency and power density, electrode spacing, pressure and gas chemistry. For chambers having electrodes on the order of two to three meters in two dimensions, arcing may be experienced at such low applied RF power levels that useful films and/or sufficiently useful deposition rates and commercial productivity cannot be achieved.
Thus, there is a need for an improved electrode suitable for use in large area PECVD chambers and the like.